It is known to backup data stored on a primary storage such as a hard disc of a computer system on a magnetic tape, which is accessed via a tape recording apparatus. One of the main reasons for using magnetic tapes as a backup storage medium is that it provides a stable, reliable and relatively cheap option for storing large volumes of backed-up data.
An application which is a computer program product hosted by a computer system that is linked with the tape recording apparatus can provide the data to be backed-up via the drivers of the tape recording apparatus to the tape recording apparatus. The data is typically provided as a sequence of data blocks, wherein each data block has a pre-given block size, e.g., 256 kilobytes.
The data blocks provided by the application are according to prior art written by the tape recording apparatus to the tape drive and only checked for writing errors on the tape recording apparatus side. The application itself does not check during the writing process if the written data blocks have been correctly written to the tape. This is done to keep the tape recording apparatus operating in streaming mode so that the write throughput and correspondingly the performance of the tape recording apparatus is kept at a high level. In order to verify that the data blocks have not been corrupted and written correctly to the tape recording apparatus, the application can read the complete tape again. This is usually done when the tape recording apparatus is not used for backup operations and might be days, weeks or even years later with respect to the point in time when the data have been provided to the tape recording apparatus. This is from an application point of view not ideal as, when the corruptions are detected, the initial data that has been stored might not be available anymore.
There is, therefore, a need for an improved method of detecting a corruption in a data block and for an improved data processing system that allows for the detection of corruptions, in particular right after the data block has been written to the tape. There is, therefore, further a need for an improved tape recording apparatus.